Automatic stoker



Dec. 17, 1940. A. E. PAIGE AUTOMATIC STOKER Filed May l1, 1958 Jil l r l. yy .l l x I r l l l. II llxnpJNllln. IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII i Patented Dec. l17, 1940 UNITED TATES .PA TENT 'GFF IC E AUTOMATIC sToKER Arthur E. Paige, Philadelphia, Pa. Application May 11, 193s, serial No. 207,249 4 claims. (el. 11o-45) Letters PatentI of the -United lStates No. 2,106,621 was granted to me January25, 1938, for an-Improvement in underfeed fire pots, which includes a hollow base for reception fof `air under v pressure, an annular grate extending above said base and formed of acircular series of sectoral grate bars, the `edges ofwhich overlap and form air passages between the bars through which air is directed through the grate tangentially in vortical vertical streams. The object and effect of this invention is to provide simple and effective means for positively )feeding coal, directlyfrom an ordinary bin, upwardly into such a grate, at a uniform rateY whichv is readily variable by an unskilled user, and insuring that the ashes and any clnkers formed upon `the top ofthe grate shall lbe discharged from the circumferential edge thereof.

My invention avoids the use of friction driving :520 belts ofthe prior art, and includes the Avarious novel features of constructioneand arrangement hereinafter more denitelyspecied. In said drawing: Fig. I is a plan view of van vautomatic Stoker 25 mechanism conveniently embodying my invention; the coal conveying tube and its appurtenances at the left hand -end thereof being partly broken away to permit that illustration to be made on a larger scale than if the complete eX- .30 tent of said `tube and its appurtenances were shown.

Fig. II is a longitudinal vertical sectional view of the structure shown-in Fig. I.

Fig. III is an elevation of the left hand end 35 of thestructure Yshown in Figs. I and VII; part of the structure shown `at the right hand end of Figs. I and II being broken away in Fig. III.

Fig. -IV is a plan view of one of the sectoral grate bars shown in section at the right hand end 40 of Fig. I.

Fig. 1V is an inverted plan view of said grate bar shown in Fig. IV.

Fig. VI is a fragmentary plan sectional View taken on the line VI, VI in Fig. II, showing the 4" tangential lair passages 4betweenthegrate bars.

In said gures; I is a cast iron cap rigidly connected with the cylindrical tube 2 to provide a coal inlet 3 at the left hand end portionof said tube which is there reduced to semi-cylindrical trough shape. Said cap I and the tube 2 are extended into a bin, hopper, or other suitable re-` ceptacle A, in'which .coal may be piled over them, above the floor 4', vto gravitate .into said tube, 5 at inlet 3.l y

Coal is conveyed through said tube `2 from said inlet 3, toward the right in Figs. I and II, by means of the `reciprocatory conveyer plunger bar 5 which has wedgeshaped projections 5 adapted Ato engage comminuted coal and push it to the -5 rightbut to release the coal and permit the bar to slide through Yit to the left in Figs. I and II.

As-v indicated in Fig. III, said wedge shaped projections 5 on the bar k5 are .of inverted U- shape. I-Iowever, the left hand end portion 5" of 10 said bar is .conveniently vrectangular in cross section as indicated in dotted lines in Fig. III, and fitted to reciprocate through a similarly shaped bearing in said cap I to hold said bar in the upright position shown in Fig. III. 15

The electric motor 6, whichis resilently connected with the base l, as best shown in Figln; is arranged to reciprocate said coal conveyer bar 5 by providing the extension 8 of the motor' armature'shaft 8' with the vworm 9, shown in Fig. II, 30 invengagement with -the gear I0. Said gear is journaled on thestationary stud II in the gear box I2 which is rigidly connected with said base I and affords bearings for said shaft extension 8 at-opposite ends oflsaid worm 9. Said gear I0 25 has the upwardly extending crank stud I4 rigidly secured therein and carrying the roller I5. Rotation of said worm 9 causes said gear III to turn counter-clockwise in said box I2 with the crank I4 and its roller I5 projecting upwardly through 30 the circular opening I6 in the lid I'I of said box I2 which is concentric with the axis rof said gear stud II. Said lid I'I has parallel guide ribs I8 projecting upwardly from the top thereof to guide the slide bar which has the slot 2l fitted over said roller I5, as shown in Fig. II. Said slide bar 2i) has the slot 22 fitted over the -upwardly projecting flange 23 of said coal bar 5, by which said bar is reciprocated. Said slide bar 2o is rigidly Connected by the screw 24 with as 40 supporting tube 25 which is mounted to reciprocate in the bearing 26 of the standard which includes the pair of legs 42'I shown in Fig. III. Said screw 24 is axially adjustable through the lug 20 on said slide bar 20 so that the stroke of said 4 bar 25 may be'varied in accordance with the amount of coal which it is desired to progress to the right in .said coal tube 2 at each stroke of said bar 2i).k n

It is to be understood that the arrangement u above described is such that with the screw 24 set in the position shown in Figs. I .and II; the slide ybar 20 .and the coal bar 5 are caused to reciprocate to the full extent of throw of .the

crank I4, but, said screw 24 may be adjusted toward the right to permit lost motion of the slide bar` 20 with respect to the coal conveyer bar 5 when said bar 20 is moved to the left in Figs. I and II and thus make the stroke of the coal bar 5 less than the stroke of the slide bar 20 which is constantly that of the throw of the crank I4,

Said coal conveyer tube 2 is rigidly connected with the elbow 28, conveniently by the set screws 29, and said elbow supports the hollow base 3|! with which it is rigidly connected, conveniently by a circular series of three bolts 3|.

As shown in Figs. I and III, said air base 30 has the air inlet 3| in tangential relation to the axis of said base and air under pressure is delivered into said base through the air conveyer tube 32 which is rigidly connected vwith `said inlet 3l, conveniently by set screws 34, and also rigidly connected with the outlet 35 `ci the fan casing 36 in which the fan wheel 31 is carried on the end of the shaft 8. i

Air is admitted to said fan casing 36 through the cylindrical tubular inlet 38, in coaxial relation with said shaft 8. The effective areaof said air inlet 38 is variably predetermined by the valve disk 39 supported by the axial screw 4U iixed in said disk, which is in engagement with the axial hub nut 4| in the spoked web 42 in the side of said casing 36.`

`Said supporting tube 25, for the slide bar 20, has its right hand end, shown in Fig. II, engaging as a nut, the screw-threaded shank of the coupling 25'. As shown in Fig. I, said coupling 25 extends between the bifurcations of the lower end of the link 44 with which it is connected by the pivot bolt` 45. The upper end of said link 44 extends between the bifurcations of` the bracket 46 with which it is connected .by the pivot bolt 41. Said bracket 46 is rigidly connected with the rockable ring 48 which has pivot brackets 49 at diametrically opposite sides thereof mounted to rock on respective pivot stud bolts ilyrigidly connected with the opposite sides of said air base30, as follows:

As shown in Fig. I; the upper rim of said air base 30 has three outwardly projecting lugs 30 With respective bolts 5I extending therethrough holding the ash ring 52 in rigid relation `with said air base 30. As shown in Fig. II; the` upwardly extending flange `28 on said coal elbow 28 and the circular inner edge of the bottom of said airbase 30 rigidly connected therewith afford opposed cylindrical surfaces between which the lower ends of sectoral grate bars 53 are tted to prevent their displacement insaid base 30. Each of said bars 53 has its `substantially'flat upper end extending beneath said ashrring 52 and resting loutwardly against the upper rim of said air base 3|]V which serves as an annularsuppor-t for `said series of grate bars which` form an annular grate in coaxial relation with said` air base 30. f

Referring to Figs. IV, V, and VI; each of said grate bars 53 has an inwardly convexed surface to support the fuel, and has corrugations 53 extending outwardly along one radial edge of the bar and consequently cireumferentially in the grate. The` opposite radial edge of each bar is smooth and overlaps the corrugated edge of the adjoining bar, in radially spaced relation so as to form air passages 54 between said corrugations on each bar 53 and between said bars, whereby, air supplied to the interior of said base 30 `under pressure from said fan wheel 31 escapes through the grate to the interior thereof and any fuel thereon, said air passages between the bars directing the air through the grate tangentially in vortical vertical streams.

It is to be understood that the construction above described is such that at each revolution of said worm gear lll` coal is underied through the coal conveyer tube 2 and elbow 28 to said annular grate and, said ring 48 is rocked to insure that ashes and any clinkers formed at the top of the grate, upontheash ring 52, shall be 10 discharged downwardly rfrom `the circumferential edge of the latter.

i. As indicated in Fig.` II; I nd it convenient to form said coal conveyer tube 2 in two sections which are abutted at 2', and connected by two metalstraps 55and four tap bolts 55'. Said sections of tube 2 are respectively rigidly upheld against Web 1' of base 1 by U-bolts 56and 51 provided with nuts above said web. Such construction and arrangement permit the convenient 20 with the distance of the supply of coal from the .30

Furthermore, I prefer to provide the `right hand endof said coal conveyer bar 5 with a section whichis `in articulated relation with the other portionofsaid bar` with which it is 35 connected bythe pivot lil.;` Saidsection 60 serves as` apoker which is not` only reciprocated by and with the bar 5 but has an up and` down rocking rnovement .beneath the mass of coal in` the elbow 28 `to `insure the proper underfeeding movement lthereofiinto the annular grate.

I also nd it convenient to provide `the bottom of the air base 30 with the rectangular vdownwardly yextending outlet 62 through which any so-calledTly ashf which may happen to gravitate into the airbase `may be readily discharged by the compressed air with which said base is supplied by theifan wheel 31. i The fly ash outlet` 62 is normallyfclosed by the door 63which is hinged upon the pivot kpin `64` in said outlet 62 and has the downwardly extending lug 65 for pivotal connection `with theright hand end of the door operating rod 61 which is prevented from' escaping from said door by the cotter pin 68 extending through the end of said rod.y Said rod 61 is supported near its left hand end by the guide plate 10 upheld against the web 1 of the base 1 by the Urbolt 56.y As shown in Fig. II, the left handA endof said rod 61 is bent to form the handle 61 and connected by the tension spring `1| with ,the screwstud 12 in said base 1.

The stress of said spring 1l continually tends to hold `the door 63 shut in the position shown in Fig.1II4,`but said door may be momentarily opened by the operator pulling said rod 61 by its handle" 61. toward the left in Fig. II; whereupon, anyfy ash in thelair base 30 is discharged downwardlytherefrom, by a blast of air from saidfar base 30.

I have notprovided any support for said stoker mechanism within'the furnaceinclosure 13, becauseany such support would interfere with the removal `of ashes from the oor 4. The legs 21 attached to the coal conduit 2, outside of said inclosure 13, uphold said conduit and the air base, grate, and their appurtenances, with considerable clear vertical space beneath said conduit, to facilitate the removal of ashes from said iioor. Moreover, the fly ash outlet 62 is thus upheld, above said floor 4I so that all fly ashes may be delivered through said outlet into the convection air current which is passing upward, above said floor, through said inclosure 13 to the stack, to prevent the ashes from being blown backward out of said inclosure.

I prefer to provide thev slotted portion of said slide bar 26 with drilled sockets holding bearing balls 14 and 15 respectively bearing upon the top of said gear box lid I'I and the guide ribs I8, to facilitate the reciprocation of said bar 2U. In order to exclude dust from said box; I find it convenient to provide the circular dust guard disk T6 in coaxial relation with said gear il) and to rigidly connect the same with said gear by the crank stud i4, which has the nut I4' at its top, bearing on said disk. I also mount in the ends of the link 44 circular series of rollers bearing upon the pivot bolts 45 and 4l which are respectively held stationary in said link 44 and in the bracket d6. To eliminate dust from the elbow 28 I provide a group of small sieve holes 28 in the bottom thereof.

However, I do not desire to limit myself to the precise details of construction, arrangement, or method of operation herein set forth; as it is obvious that various modifications may be made therein without departing from the essential features of my invention as defined in the appended claims.

I claim:

1. In `an automatic stoker mechanism, the combination with an annular grate; of means for underfeeding fuel into said grate, including a tube with an upwardly curved elbow having one end in coaxial relation with said grate, said tube extending radially with respect to said grate; a reciprocatory conveyer plunger bar, mounted to reciprocate in said tube; an upwardly extending iiange on said conveyer, projecting through a slot in the top of said tube; means for reciprocating said conveyer by said flange, including a slide bar having a slot fitted over said flange, and bearing means rigidly connected with said tube at the top thereof for supporting said slide bar for reciprocation; driving means for reciprocating said slide member with constant amplitude; means for adjustably varying the extent of reciprocation of said conveyer, with respect to said slide bar, including a single, axially adjustable screw mounted in said slide bar for contact with one edge of said flange; means for holding said screw in said slide bar in adjusted position; and means for reciprocating said slide bar; whereby, the rate of feeding fuel to said grate may be varied in relation to the constant speed of said driving means, by merely axially adjusting said single screw.

2. In an automatic stoker mechanism, the combination with an annular grate; of means for underfeeding fuel into said grate, including 'a tube with an elbow having one end in coaxial relation with said grate, said tube extending radially with respect to said grate; a reciprocatory conveyer plunger bar, mounted to reciprocate in said tube; an upwardly extending iiange on said conveyer, projecting through a slot in the top of said tube; means for reciprocating said conveyer by said flange, including a slide bar having a slot fitted over said ange, and bearing means rigidly connected with said tube at the top'thereof for supporting said slide bar for reciprocation; driving means for reciprocating said slide bar with constant amplitude, including an electric motor; means for adjustably varying the extent of reciprocation of said conveyer, with respect to said slide bar, including a single, axially adjustable screw mounted in said slide bar for contact with one edge of said flange; means for holding said screw in said slide bar in adjusted position; said means for reciprocating said slide bar, including a worm gear mounted on a vertical axis and having a crank engaging a slot in said slide bar; and a worm on the armature shaft of said motor in mesh with said worm gear.

3. In an automatic stoker mechanism, the combination with an annular grate; of means for underfeeding fuel into said grate, including a tube with an elbow having one end in coaxial relation with said grate, said tube extending radially with respect to said grate; a reciprocatory conveyer plunger bar, mounted to reciprocate in said tube; an upwardly extending flange on said conveyer, projecting through la slot in the top of said tube; means for reciprocating said conveyer by said flange, including a slide bar having a slot fitted over said flange, and bearing means rigidly connected with said tube at the top thereof for supporting said slide bar for reciprocation; driving means for reciprocating said slide bar with constant amplitude, including an electric motor; means for adjustably varying the extent of reciprocation of said conveyer, with respect to said slide bar, including a single, axially adjustable screw mounted in said slide bar for contact with one edge of said flange; means for holding said screw in said slide bar in adjusted position; and means for reciprocating said slide bar, including a gear mounted on a vertical axis and having a crank engaging a slot in said slide bar, a worm engaging said gear, and an electric motor operatively connected with said worm; whereby continuous rotary movement of said gear and crank effects reciprocatory movement of said slide bar and conveyer plunger, but, the amplitude of movement of said conveyer may be adjustably varied with respect to the movement of said slide bar by adjustment of said single screw.

4. In an automatic stoker mechanism, the combination with an annular grate; of means for underfeeding fuel to said grate, including a tubular conduit in radial relation with the grate and having an upwardly curved elbow with one end in coaxial relation with the grate; a reciprocatory conveyer plunger bar, mounted to reciprocate in said conduit; an upwardly extending flange on said conveyer, projecting through a slot in the top of said conduit; means for reciprocating said conveyer by said ange, including a slide bar; bearing means rigidly connected with said tube at the top thereof for supporting said slide bar for reciprocation; driving means for reciprocating said slide bar with constant amplitude; means for adjustably varying the extent of reciprocation of said conveyer, with respect to said slide bar, including a single, axially adjustable, screw mounted in said slide bar for contact with one edge of said flange; and means for holding said screw and said slide bar in adjusted position; whereby, the rate of feeding fuel to said grate may be varied in relation to the constant speed of said driving means, by merely axially adjusting said single screw.

ARTHUR E. PAIGE. 

